Liu Zenghe,Fang Zizheng,Zheng Ning,Yang Kexuan,Sun Zhuo,Li Sujing,Li Wei,Wu Jingjun,Xie Tao
Polyurethane thermosets are indispensable to modern life, but their widespread use has become an increasingly pressing environmental burden. Current recycling approaches are economically unattractive and/or lead to recycled products of inferior properties, making their large-scale implementation unviable. Here we report a highly efficient chemical strategy for upcycling thermoset polyurethane foams that yields products of much higher economic values than the original material. Starting from a commodity foam, we show that the polyurethane network is chemically fragmented into a dissolvable mixture under mild conditions. We demonstrate that three-dimensional photo-printable resins with tunable material mechanical properties—which are superior to commercial high-performance counterparts—can be formulated with the addition of various network reforming additives. Our direct upcycling of commodity foams is economically attractive and can be implemented with ease, and the principle can be expanded to other commodity thermosets.
Particulate matters (PMs) pollution and bacteria severely affect human health. Fibrous filters have shown great potential in intercepting PMs and bacteria. However, developing a novel respirator material endowed with multi-functions, such as efficient filtration, antibacterial activity, directional moisture transport and biodegradability is still challenging. Herein, a multifunctional air filtration membrane with hierarchical structure was fabricated by sequentially electrospinning poly (ε-caprolactone) (PCL) fibrous membrane, PCL/gelatin fibrous membrane and PCL/gelatin/ε-poly (L-lysine) (ε-PL) fibrous membrane. The fabricated trilayered fibrous membrane exhibited high PM filtration efficiency and a low pressure drop. Moreover, the fibrous membrane possessed excellent antibacterial activity due to the incorporation of ε-PL. In addition, the trilayered fibrous membrane provided directional water transport performance by the combination of hydrophobic fibrous layer and hydrophilic fibrous layer, thus improving the comfort of the wearer. Importantly, benefiting from the biodegradability property of PCL, gelatin and ε-PL, the fibrous membrane was biodegradable, which could decrease the burden on the environment. The fabricated trilayered fibrous membrane not only shows promising potential as a highly efficient, antibacterial, moisture-wicking and biodegradable air filtration membrane, but also offers a versatile strategy to design a multifunctional face mask.
危险品化学品经营许可证（带存储）